geology - board of studies your answers in either blue or black pen ... new zealand journal of...

DIRECTIONS TO CANDIDATES

• Board-approved calculators may be used.

Section I—Core

• Attempt ALL questions.

• Part A 15 multiple-choice questions, each worth 1 mark.Complete your answers in either blue or black pen on the Answer Sheet provided.

• Part B 10 questions, each worth 3 marks.Answer this Part in the Part B Answer Book.

• Part C 6 questions, each worth 5 marks.Answer this Part in the Part C Answer Book.

• Write your Student Number and Centre Number on the cover of each Answer Book.

• You may keep this Question Book. Anything written in the Question Book will NOT bemarked.

Section II—Electives

• Attempt ONE question.

• Each question is worth 25 marks.

• Answer the question in a SEPARATE Elective Answer Book.

• Write your Student Number and Centre Number on the cover of the Elective Answer Book.

• Write the Course, Elective Name, and Question Number on the cover of the Elective AnswerBook.

• You may ask for extra Elective Answer Books if you need them.

341

HIGHER SCHOOL CERTIFICATE EXAMINATION

2000

GEOLOGY2 UNIT

Time allowed—Three hours(Plus 5 minutes reading time)

SECTION I—CORE

(75 Marks)

Attempt ALL questions.

PART A

Questions 1–15 are worth 1 mark each.

Instructions for answering multiple-choice questions

• Complete your answers in either blue or black pen.

• Select the alternative A, B, C or D that best answers the question. Fill in the responseoval completely.

Sample: 2 + 4 = (A) 2 (B) 6 (C) 8 (D) 9

If you think you have made a mistake, put a cross through the incorrect answer and fill inthe new answer.

If you change your mind and have crossed out what you consider to be the correct answer,then indicate the correct answer by writing the word correct and drawing an arrow asfollows.

A B C D

correct

A B C D

A B C D

2

1 What is the asthenosphere?

(A) A mobile zone in the upper mantle

(B) A mobile zone immediately below the crust

(C) A rigid zone in the upper mantle

(D) A zone that does not transmit S waves

2 A rich gold-bearing ore body is being mined by open-cut methods. Which factor isLEAST likely to affect the economic viability of the mine?

(A) Age of the mineralisation

(B) Type of host rock

(C) Tonnage of the ore body

(D) Number of rainy days per year

3 The diagram shows a situation in which two lithospheric plates, P and Q, are colliding.

Which of the following correctly summarises the situation?

(A) P is an oceanic plate, Q is a continental plate, and an island arc is locatedbelow T.

(B) P is an oceanic plate, a Benioff zone is located at Zone S, and a trench is located atU.

(C) Q is an oceanic plate, P is a continental plate, and a trench is located at R.

(D) A Benioff zone is located at Zone V, a trench is located at R, and an island arc islocated at T.

Plat

e P

Plate Q

S

Zone V

R T U

Zone S

3

Minfact 64, August 1996, fig 1.

4 The diagrams in the table are all drawn to the same scale.

Only one row of information is correct. Which row is correct?

(A) A

(B) B

(C) C

(D) D

5 The mullock (waste rock) from a uranium mine commonly contains small amounts ofradioactive material that can leach into the environment. What is the best method toprevent this material from contaminating the environment outside the mine site?

(A) Screen the mine site, thus preventing access by animals that could move themullock.

(B) Crush the mullock and use it for road construction.

(C) Plant vegetation on the mullock to stabilise it and prevent wind erosion.

(D) Store the mullock in a covered pit with an impermeable lining.

0 4

4

0

km

km

Scale

A

B

C

D

Basalt

Rhyolite

Andesite

Andesite

Compositionof lava

Explosive

Quiet

Quiet

Explosive

Type oferuption

Convergentmargin

Continentalhot spot

Divergentmargin

Convergentmargin

Typical platetectonic settingVolcano shape and size

4

6 The cross-sections show the formation of a large-scale feature of the Earth’s surface.

What feature is shown?

(A) A rift valley, an example of which could be found in eastern Africa

(B) A mid-ocean ridge, an example of which could be found in the Atlantic Ocean

(C) A transform fault, an example of which could be found in western USA

(D) A trench, an example of which could be found in the Pacific Ocean

7 Which of the following rock types is most likely to be the best petroleum reservoir rock?

(A) Granite

(B) Quartzite

(C) Sandstone

(D) Shale

Brittle upper crust

Ductile lower crust

Upper mantle

Movement direction

KEY

Force direction

(I)

(II)

(III)

Sediments

Moho

15

0km

5

Tectonophysics, Vol 73, 1981, Bott, M H P,

'Crustal doming and the mechanism of continental rifting', pp1-8, (c) 1981, with permission from Elsevier Science.

8 The map shows some of the major mountain ranges of the world.

Which of the following is a mountain range formed as a result of ancient, rather thancurrent plate interactions?

(A) Andes Mountains

(B) Himalaya Mountains

(C) Rocky Mountains

(D) Ural Mountains

9 Over what time span do fold mountain ranges generally form?

(A) Tens of thousands of years (104 years)

(B) Hundreds of thousands of years (105 years)

(C) Tens of millions of years (107 years)

(D) Thousands of millions of years (109 years)

Mid-Atlantic RidgeSouthern

Alps

OwenStanleyRange

Ural Mountains

HimalayaMountains

ZagrosMountains

AlpsRocky

Mountains

AndesMountains

AppalachianMountains

6

Weyman, D, Tectonic Processes, George Allen & Unwin, London, 1981.

10 The diagram shows the pattern of magnetic reversals recorded in basaltic rocks in part ofan ocean.

What is the dominant spreading direction for this pattern to form?

11 The map shows the distribution of currently active volcanoes in Java and adjacent islands.

To which feature are the volcanoes most likely related?

(A) Continental rift zone

(B) Convergent margin

(C) Hot spot

(D) Mid-ocean ridge

N

VolcanoKEY

500 km

(A) (B)

(C) (D)

7

12 The diagram shows rock structures observed in a block of the Earth’s crust.

Where would the structures shown in the diagram have formed?

(A) At a mid-ocean ridge

(B) At a continental rift zone

(C) At an ocean-continent convergent zone

(D) At a continental hot-spot volcano

13 The diagram shows a sketch of a section through a magnesite (magnesium carbonate)deposit. Magnesium carbonate is an insoluble substance. These deposits form in hot wetclimates.

How would this magnesite deposit have formed?

(A) As a placer deposit

(B) As a residual deposit

(C) By hydrothermal activity

(D) By igneous activity

Thin or absent humus

Thick irregularmasses of magnesite

Iron and magnesium claysand aluminium hydroxides

Ultramafic rock

2

0

km

8

Hamblin, W K & Howard, J D, Exercises in Physical Geology, Burgess Publishing Minnesota, 1975, 4th ed, p 57, fig 110.

McLeish A, Geological Science, Blackie & Son, Glasgow, 1986, p 277.

14 The map shows the proposed position of a major gas pipeline from Christchurch toNelson in the South Island of New Zealand. The pipeline will cross the Alpine Fault.

The Alpine Fault is a major transform fault.

What is the dominant movement that the pipeline must be designed to withstand?

(A) Compressional movement

(B) Horizontal shear movement

(C) Tensional movement

(D) Vertical shear movement

Proposed natural gas pipelineKEY

Christchurch

168°E 172°E

168°E 172°E

44°S

Alpine Fault

Nelson

44°S

9

New Zealand Journal of Geology and Geophysics 33, 2, 1990 p 202 (c) SIR Publishing, the Royal Society of New Zealand

15 The map shows a mid-ocean ridge that separates two continental masses that werepreviously joined. The ridge has been active over the last five million years.

Which piece of land-based evidence is INCONSISTENT with the continental drift andplate tectonic hypotheses?

(A) The locations of the Allosaurus fossils

(B) The locations of the Mesozoic sedimentary basin

(C) The locations of the early Tertiary sedimentary basin

(D) The locations of the Precambrian fold belt

Active mid-ocean ridgeand transform faults

Precambrian fold belt

Early Palaeozoic fold belt

Early Tertiarysedimentary basin

Mesozoicsedimentary basin

Allosaurus fossil

KEYO

cean

Ocean

10

PART B

Questions 16–25 are worth 3 marks each.

Answer this Part in the Part B Answer Book.

16 The graph shows the weight percentage of carbon in coals of increasing rank.

(a) Describe the trend shown in the graph.

(b) Explain the trend shown in the graph.

(c) How does anthracite differ in appearance from peat?

17 The diagram shows a section through an igneous intrusion with associated hydrothermalveins. The intrusion contains 0·01% copper, whereas the veins contain 5% copper.

(a) Explain how the copper became concentrated in the veins.

(b) Name TWO other metals that could be concentrated in a similar way.

Igneous intrusion

veinsHydrothermal

Limestone

Shale

50 60 70 80 90 100Carbon (%)

Peat

Lignite

Bituminous coal

Anthracite

11

McLeish, A, Geological Science,

Blackie & Son, Glasgow, 1986, p 282.

Montgomery, C W, Fundamentals of Geology, 3rd ed, Wm C Brown, Dubuque, Iowa, 1997, p 53.Reproduced with permission of The McGraw-Hill Companies.

18 (a) (i) Name ONE physical property of the asthenosphere that is different in thelithosphere.

(ii) Briefly describe how it is different.

(b) Outline how our knowledge of the asthenosphere allows us to explain plate motion.

19 The diagram shows the plate boundaries in the Pacific Ocean region.

(a) Name the type of boundary that would form if the directions of movement werereversed along the Australian Plate–Antarctic Plate boundary.

(b) Describe TWO features characteristic of the type of plate boundary you named inpart (a).

Divergent boundary

Convergent boundary

Conservative boundary

Plate velocity (mm per year)

KEY

40

Eurasian Plate

AustralianPlate

100

Pacific Plate

60

4

80

70

60

Antarctic Plate

70

North AmericanPlate

12

Montgomery, C W, Fundamentals of Geology, 3rd ed, Wm C Brown, Dubuque, Iowa, 1997, fig 9.5.Reproduced with permission of The McGraw-Hill Companies.

20 In 1900, it was believed that the Southern Atlantic Ocean was ancient and unchanging. Itis now known that the Southern Atlantic Ocean is widening, and that South America andAfrica are moving apart.

Describe THREE pieces of ocean-based evidence that support this present view of theSouthern Atlantic Ocean.

21 (a) State TWO distinctive characteristics of a shield area.

(b) Describe the process by which a shield area forms.

22 The diagram shows a schematic cross-section through an oceanic plate, the position offive volcanic islands, and their ages.

(a) On the diagram in the Part B Answer Book, draw an arrow to indicate the directionof plate movement.

(b) (i) For this type of volcanic island chain, state the composition of the lavaerupted.

(ii) Sketch the shape of a typical volcano formed in this setting. Relate thisshape to the characteristics of the eruptions that produced it.

3·8–5·6 Ma

Sea level

2·3–3·3 Ma1·3–1·8 Ma

0–1·3 Ma0–0·7 Ma

13

23 A major engineering project recently completed in Sydney was the Airport Rail Link.This was constructed as an underground tunnel through rock and soft, waterloggedsediments.

A section of the tunnel and surrounding geology is shown.

Describe THREE different geological problems that needed to be overcome inconstructing this tunnel.

SYDNEYN

Water table

30 m

AIRPORT

KEY

Sand, silt, peat — Quaternary

Shale — Triassic

Bedded sandstone — Triassic

Jointing in sandstone

S

2 km

TUNNEL

14

24 The diagram shows a geological cross-section of a region that has the potential toproduce oil and gas.

(a) On the diagram in the Part B Answer Book, draw a line to represent a drill hole thatwould most likely strike oil and/or gas.

(b) Give TWO reasons why you chose this site.

25 The elevation of the Himalaya Mountains is maintained by two processes, plateconvergence and isostasy.

Explain the role of isostasy in maintaining the elevation of the Himalaya Mountains.

W E

KEY

Conglomerate

Shale

Sandstone

Limestone

0 1 2 km

15

PART C

Questions 26–31 are worth 5 marks each.

Answer this Part in the Part C Answer Book.

26 The diagram shows several vents in the Tongariro volcanic zone, New Zealand, andisopachs for two ash units, OK2 and OK3. Isopachs are lines of equal ash thickness. TheTongariro volcanic zone is related to a subduction zone.

(a) State the composition of the volcanic material erupted from these volcanic vents.

(b) Sketch and label a diagram to show the internal structure of this type of volcano.

(c) Describe and explain the difference between the distributions and thicknesses ofthe ash layers OK2 and OK3.

Lake TaupoKakaramea

Tihia

Lake Rotoaria

Pihanga

NationalPark Mt Ngauruhoe

Mt Tongariro

Turangi

Mt Ruapehu

100

300

200 150100

0 105

kilometres

KEY

OK2ash isopachwith ash thicknessin millimetres

OK3ash isopachwith ash thicknessin millimetres

Volcanicvent

N

200

16

New Zealand Journal of Geology and Geophysics 16, pp 397-423.

27 The diagram shows a faulted, shallow, copper ore body dipping at 20° to the east andbeing mined by open cut methods. The present cut-off grade of the ore body is3% copper. Maximum mining depth by open cut methods is 200 m. The mine is located300 km from the nearest town.

(a) Define the term grade.

(b) Explain what is likely to happen to future mining operations if the price of copperincreases.

(c) The existing open cut mine has caused a number of environmental problems. StateTWO possible problems.

(d) The deeper part of the ore body will be mined as an underground operation.Describe ONE new environmental factor that has to be considered.

Fault

F

F F

Outline of currentopen cut mine

Dep

th (

m)

200

100

0

W E

KEY: Grade

4% Cu

3% Cu

2% Cu

1% Cu

17

18

28 Diagram A is a map that shows three magnetic anomaly profiles and contour lines on anocean floor. Diagram B is a cross-section through A, B and C. Beneath Diagram B are thecore logs for drill holes A, B and C.

MagneticPolarisation

Line 2

Line 1

Line 3

+

−

+

−

+

−

1000

m

2000

m

4000

m

4500

m

2000

m

4000

m

4500

m

Core logs

Y

X

DIAGRAM B

0 100 200 300

SCALE(km)

DIAGRAM A

B C

B

C

MF1 Globigerina pearl12·5 million years

MF2 Globigerina rufus6·0 million years

Radiometric ages

A1 15 million years

B1 8 million years

C1 1 million years

Siliceousmud

Calcareousmud

Basalt

Dolerite

Gabbro

KEY

A

A

0

100

200

300

400

500

m

B

MF2

B1

A1

A

MF1

MF2

C

C1

0

2000

4000

6000

m

QUESTION 28 (Continued)

(a) Name the large-scale geological feature present in the region depicted in thediagrams.

(b) Calculate the average rate of motion, in kilometres per million years, experiencedby the rocks and sediment located at site A.

(c) What is the average rate of sediment accumulation, in metres per million years, atsite B?

(d) Explain why the magnetic signatures on Lines 1, 2, and 3 are approximatelysymmetrical about the line XY.

Please turn over

19

29 The map shows a granite body that intruded a sequence of regionally metamorphosedmudstone, greywacke and intermediate volcanic rocks. Both the granite and themetamorphic rocks have a distinct foliation that strikes approximately north-south.

Question 29 continues on page 21

N

Granite

Metamorphosedgreywacke and mudstone

Metamorphosedandesite + intermediate tuff

Quarry

2 km

Regional foliation

Strike and dipof strata

Overturned bedding

20


(a) Name a plate tectonic setting in which these rocks and structures could havedeveloped.

(b) Describe how foliation develops in rocks in such a setting.

(c) List the following events in order from oldest to youngest:

• the formation of the foliation

• the emplacement of the granite

• the formation of the mudstone/greywacke/volcanic sequence.

(d) Analysis of the granite revealed that it retains 70% of its original 40K. Use theradioactive decay curve to determine the age of the granite.

0 1000 2000 3000 4000 50000

10

20

30

40

50

60

70

80

90

100

Time (millions of years)

Perc

enta

ge o

f pa

rent

isot

ope

rem

aini

ng

40K

21

30 Fold mountains are composed of rocks representing all the major rock groups—volcanic,plutonic, regional metamorphic, contact metamorphic, and sedimentary.

Name ONE rock type from each of the five groups above that you would expect to findin a fold mountain range. For EACH of these rock types, briefly explain how it becomespart of a fold mountain range.

31 The diagram shows the apparent polar wandering curves for the African Plate (solid line)and Arabian Plate (dashed line).

(a) What is an apparent polar wandering curve?

(b) Using the apparent polar wandering curves, describe the motion of the AfricanPlate and Arabian Plate relative to each other over the past 600 million years.

(c) Describe the data that you would need if you were required to construct a polarwandering curve for the Australian Plate for the past 200 million years.

00

N

S

600 million years ago




Present

Dates of apparentpole positions (approx.)

Arabian PlateAfrican Plate

KEY:

Apparent polarwandering curves

Arabian Plate

22

Reproduced with the permission of The McGraw-Hill Companies.Montgomery, C W, Fundamentals of Geology, Wm C Brown, Dubuque, Iowa, 3rd ed 1997, p 144.

SECTION II—ELECTIVES

(25 Marks)

Attempt ONE question.

Answer the question in a SEPARATE Elective Answer Book.

Pages

QUESTION 32 Contemporary Sedimentary Processes .................. 24–27

QUESTION 33 Igneous Rocks ....................................................... 28–31

QUESTION 34 Economic Geology ................................................ 32–33

QUESTION 35 Regional Geology .................................................. 34–35

QUESTION 36 Palaeontology ........................................................ 36–41

23

QUESTION 32 Contemporary Sedimentary Processes

In this elective you have studied the sedimentary processes that are occurring in apresent-day depositional environment. You will have undertaken some field work andlaboratory investigations in order to study the environment and produce a report.

(a) Name the depositional environment you studied, and state its location.

(b) Draw and label a full-page sketch map of the area you studied. The map shouldinclude:

(i) sampling locations;

(ii) direction(s) of sediment transport;

(iii) locations of features of particular interest, such as sedimentarystructures, sediment sources, and locations of human influence onsedimentary processes.

(c) Describe, in detail, the methods that were used to:

(i) determine the composition, grain size, distribution and shape of thesediment grains;

(ii) measure the velocity of the transporting medium;

(iii) determine the source of the sediment.

(d) (i) Use labelled diagrams to illustrate TWO sedimentary structures thatwere characteristic of the environment.

(ii) Describe the composition and average grain size of the sediment foundin one of these structures.


3

5

3

24

Marks


(e) List THREE organisms, excluding humans, found in the environment. Discusshow these organisms interacted with the environment, and how they affected thesedimentary processes you observed.

(f) Describe, in detail, ONE significant effect that human activity has had on thesedimentary processes that you observed in your study area. Assess its influencein changing the natural processes.

(g) You are on a field trip to another region and you find an exposure of sedimentaryrocks in a cliff face. This exposure contains some, but not all, of the structuresyou observed in the present-day depositional environment you studied.

(i) Briefly describe the field and laboratory methods you would use tointerpret the environment in which the sedimentary rocks in the cliff faceformed.

(ii) Explain how you would support an hypothesis that the rocks in the cliffface might have formed in a different depositional environment from theone you studied.


4

2

3

25

Marks


(h) Diagram A shows four frequency histograms, A, B, C, and D that show the grainsize distributions of four different sediments.

Diagram B shows cumulative frequency curves labelled I, II, III and IV, for theSAME four sediment samples shown in Diagram A. They are in no particular order.


11024

1256

14

0

20

40

1164

116

Cum

ulat

ive

per

cent

Grain size (mm)

60

80

100I II III

IV

DIAGRAM B

A

12

14

18

116

132

0

25

50

116

B

14

1256

0

25

50

12

14

18

116

C

4 2 10

25

50

164

D

116

11024

1256

0

25

50

Wei

ght p

er c

ent

Grain size (mm)

DIAGRAM A

164

164

1128

18

132

1128

132

1128

1512

5

26

Marks

Blatt, H, Middleton G, and Murray, R, Origin of Sedimentary Rocks, Prentice-Hall, Ebglewood Cliffs, NJ, 1972, p 35.


(i) Match each frequency histogram (A, B, C and D) with the correctcumulative frequency curve (I, II, III or IV).

(ii) From the cumulative frequency curve, give:

1 the MEDIAN (50%) grain size of the finest sediment sample;

2 the sediment sample that displays the best sorting.

(iii) The four sediment samples were obtained from a river, a desert sanddune, a deposit of wind-blown silt, and a deep marine clay.

Match each of the histograms with its correct source, giving reasons foryour choices.

End of question

27

Marks

QUESTION 33 Igneous Rocks

(a) This question relates to the diagrams and table shown.

The four photomicrographs (I, II, III, and IV) show a sequence of fourconsecutive stages in the cooling of a 30 m thick lava flow. The samples weretaken from the centre of the flow at five-year intervals. The temperature of eachsample is given at the top left-hand corner of the photomicrograph. The sampleswere instantly cooled to room temperature.

The table shows the major element composition of the lava, as weight per centof oxides.


Weight per cent

47·52

3·29

15·95

3·16

8·91

0·19

5·18

8·96

3·96

1·09

0·64

1·36

99·85

Oxide

SiO2

TiO2

Al2O3

Fe2O3

FeO

MnO

MgO

CaO

Na2O

K2O

P2O5

H2O

Total

gas bubble

I

1250°C

B CIlmenite

1025°C

IV

mm0 2

A

II

1170°C

III

1130°C

11

28

Marks


(i) Determine a name for the lava, using its major element composition.

(ii) Name the minerals labelled A, B, and C.

(iii) Describe the cooling history of the lava flow, and give an order ofcrystallisation for the minerals present.

(iv) 1 Name the texture shown in photomicrograph I.

2 Explain why samples taken from the base of the lava flow have thesame texture as that shown in photomicrograph I.

(v) Name the texture shown in photomicrograph II.

(vi) 1 Name the rock type that is the plutonic equivalent of this lava.

2 Draw and label a sketch that shows the texture of the rock type younamed in part (vi) 1.

(vii) The rock type shown in photomicrograph IV is composed mostly ofcrystals. Compare the texture shown in photomicrograph IV with thetexture shown in the sketch you drew for part (vi) 2. Explain anydifferences.

(viii) Name the type of volcano that would be entirely composed of this lavatype, and indicate a typical plate tectonic setting for this volcano.


29

Marks


(b) This question relates to the sketch and the geological map that show the igneouslandforms called Pilgrim’s Hat and Propeller Rock.


View looking north

North Blade

Propeller Rock

West Blade

SouthBlade

Pilgrim’sHat km

0 1

N

Microgranite, age 15·5 ± 0·3 million years

Microdiorite, age 15·6 ± 0·3 million years

Mudstone, age 155 million years

KEY

9

30

Marks


(i) What type of igneous structure is Pilgrim’s Hat?

(ii) What type of igneous structure is North Blade?

(iii) The land surface around Propeller Rock and Pilgrim’s Hat formed about5 million years ago. Use a series of labelled diagrams to show howPilgrim’s Hat, Propeller Rock, and the Blades formed.

(iv) Chemical analysis of the microdiorite and the microgranite that formPropeller Rock and Pilgrim’s Hat indicates that these two rock typesformed from the same parent magma.

1 Name a possible parent magma.

2 Explain, in detail, how the microdiorite and the microgranite formedfrom the parent magma.

(c) (i) Name TWO types of economic deposits, other than hydrothermal veindeposits, commonly associated with intrusive igneous rocks.

(ii) Briefly describe how EACH type of economic deposit you named inpart (c) (i) forms.

End of question

5

31

Marks

QUESTION 34 Economic Geology

In this elective, you studied TWO of the following:

• an economic deposit formed by igneous and/or metamorphic processes;

• an economic deposit formed or concentrated by weathering or sedimentary processes;

• an engineering project.

(a) For an economic deposit you studied, answer the following questions.

(i) Name the economic deposit.

(ii) Describe the resource, the final product or products, and its/theireventual use or uses.

(iii) Draw and label a cross-section of the deposit. Show both the economicdeposit and the surrounding geology.

(iv) Describe in detail the geological processes that were responsible forforming and concentrating the deposit.

(b) For EITHER a second economic deposit, OR an engineering project youstudied:

(i) Name the deposit or project.

(ii) Name one exploration or testing method used in this deposit or project.For this method, describe:

1 why it was used;

2 the procedures used;

3 the results obtained.

(iii) 1 Describe TWO environmental factors that influenced thedevelopment or operation of the deposit or project.

2 Choose ONE environmental factor described in part (b) (iii) 1.Explain the effect it had on the operation or maintenance of thedeposit or project.

(iv) Explain how the geology of the site influenced EITHER the design andconstruction of the project, OR the extraction method used in the project.


10

10

32

Marks


(c) The diagram shows one scheme that can be used to categorise reserves andresources to indicate areas of immediate economic interest.

(i) With reference to the diagram, state the difference between the termsindicated, inferred, and proved reserves.

(ii) Name and briefly describe TWO factors that could move an ore bodyinto or out of the ‘Zone of economic uncertainty’.

(iii) With reference to the diagram, distinguish between Reserves andResources.

End of question

Total resources

Identified

InferredHypothetical

(In knowndistricts)

Speculative(In undiscovered

districts)

Undiscovered

R e s e r v e s

Eco

nom

ic

Zone of economicuncertainty

Increasing degree of geological assurance

Incr

easi

ng d

egre

eof

eco

nom

ic fe

asib

ility

Sub

-eco

nom

ic

IndicatedProved

Measured

Total resources

Identified

InferredHypothetical

(in knowndistricts)

Speculative(in undiscovered

districts)

Undiscovered

R e s e r v e s

Eco

nom

ic

Zone of economicuncertainty

Increasing degree of geological assurance

Incr

easi

ng d

egre

eof

eco

nom

ic fe

asib

ility

Sub

-eco

nom

ic

Indicated

R e s o u r c e s

Proved

Measured

5

33

Marks

Evans A M, Ore Geology & Industrial Minerals: An Introduction, Blackwell Scientific Publications, Boston, 1993, p 24.

QUESTION 35 Regional Geology

In this elective, you studied one of the following regions:

• North-western Fold Belt

• Central and Southern Fold Belt (northern areas)

• Central and Southern Fold Belt (southern areas)

• New England Fold Belt

• Sydney Basin.

Name the region you studied.

(a) (i) Draw a stratigraphic column for the region you studied. On the column,show the major lithological units and unconformities, using appropriatesymbols. Do NOT include intrusive igneous rocks.

(ii) Label each unit on the right-hand side of the column. Include the nameof the unit and the names of the major rock types.

(iii) Explain why a stratigraphic column is a useful tool for understanding thegeological evolution of the region.

(b) The geomorphology, land use, and vegetation of an area are controlled by theunderlying lithology. Choose TWO of the major lithological units from yourregion, and describe how these units have influenced the geomorphology andEITHER land use OR vegetation.

(c) (i) Name and draw a diagram of a major structural feature in the region youstudied. Label the lithological unit(s) in which the feature occurs.

(ii) Describe the significance of this structural feature in terms of thegeological development of the region.

(d) The region includes an economic deposit or mine.

(i) Name the deposit or mine.

(ii) Name the economic commodity in this deposit.

(iii) Describe the formation of the deposit.


3

3

4

4

34

Marks


(e) The region contains a feature of special geological interest.

(i) Name the feature.

(ii) Describe, in detail, the formation, construction or development of thisfeature.

(f) (i) Name the types of boundaries between the region you studied and TWOadjacent regions.

(ii) Describe the significance of each of the boundaries named in part (f) (i),in terms of the geological development of the region.

(g) You will have used a number of methods to investigate the region you chose.

(i) Maps and air photos are sources of information. For each, describe thetype of geological information you can obtain.

(ii) Explain the meaning of a scale of 1 : 100 000 when given on a map or airphoto.

(iii) Name TWO other sources of information you used during yourinvestigation of the region you chose. Evaluate these sources in terms oftheir usefulness.

End of question

5

3

3

35

Marks

QUESTION 36 Palaeontology

(a) The diagram shows the number of genera of animal groups since the Triassic.

(i) What was the maximum number of dinosaur genera?

(ii) When did the first reef corals evolve?

(iii) Suggest ONE reason why the number of dinosaur genera increasedduring the Jurassic.

(iv) State the maximum number of reef coral genera, and when this numberwas achieved.

(v) Compare the trend in the number of dinosaur genera with the trend in thenumber of solitary coral genera and Globigerines during the Cretaceous.

(b) Discuss, in detail, ONE probable cause for the changes in the number of generaacross the Cretaceous–Palaeocene boundary.

(c) (i) What is a missing link?

(ii) Explain why many animal groups have missing links in their fossilrecord.


2

3

Cretaceous Pal. Eoc. Olig. Mio. Pl. Q.JurassicTriassic

Reef corals

Dinosaurs

Globigerines

Living reef corals

Reef corals

Solitary corals

Millions of years before the present

120

100

0

20

40

60

80

225 200 175 150 125 100 75 50 25 0

Num

ber

of g

ener

a

5

36

Marks

Berggren, W A & Van Couvering, J A (eds), Catastrophes and Earth History:

The New Uniformitarianism, Princeton NJ, Princeton University Press, 1984.


(d) The diagrams show three fossils A, B, and C.

(i) To which group does each of the fossils A, B, and C belong?

(ii) Select ONE of these groups.

1 Name the group.

2 When did this group first appear?

3 When did this group become extinct?

4 Describe the environment in which this group lived.

5 Describe the major morphological changes that occurred in thisgroup as it evolved.

(iii) For ONE of the above groups, OTHER than the one you selected inpart (ii), discuss why it is difficult to classify members of this group tospecies level.

(e) (i) What is evolution?

(ii) How is the fossil record useful for demonstrating evolution? In youranswer, use examples from ONE fossil group, but not the same groupselected in part (d) (ii).


3

7

37

Marks

McDonnell, Massey et al, Enquiring into the Earth,

Reprinted with permission of Pearson Education Australia, www.longman.com.au.

Longmans 1968, pp 136-137. Branagan D, Beneath the Scenery:

Science Press, Marrickville, NSW, 1971, p53.Geology for senior students,


(f) Answer EITHER (i) OR (ii) OR (iii).

EITHER

(i) Select TWO fossil assemblages from different palaeo-environments.

1 Discuss how the fossils in each assemblage might be used tointerpret the palaeo-ecology of the assemblages.

2 Discuss evidence, other than fossils, that you might use to interpretthe palaeo-ecology of each assemblage you selected.

OR


5

38

Marks


(ii) The diagrams show an artist’s impression of Australopithecus andNeanderthal man.

Australopithecus Neanderthal man

1 Which of the two is more closely related to modern people? Justifyyour answer.

Diagram A shows a cross-section through the Keilor Terrace,Maribyrnong River, Victoria. Diagram B shows an Aborigine’s toolfound at the level marked by X.

DIAGRAM A

DIAGRAM B

2 What is the age of the Aborigine’s tool?

3 How might you verify the age of the tool?

4 What evidence would you look for to determine the lifestyle of theowner of the tool?

OR


Top view Side view

Bedrock

15 000Clay

26 000

36 000

Keilor Terrace

m

3210

Sand X

18 000

Inferredminimumage (years)

Radiocarbondate (years)

KEY

39

Marks

Simpson, Pittendrigh & Tiffany, Life: An Introduction to Biology, Routledge & Kegan Paul, 1958, fig 32.16

Continent of Hunter-gatherers: new perspectives in Australian prehistory, Cambridge Uni Press, Melbourne, Vic, 1997. Reprinted with the permission of Cambridge Uni Press.


(iii) Diagram C shows the age range of micro-fossils recovered from DeepSea Drilling Project (DSDP) drill holes.


PleistocenePliocene

Miocene

Oligocene

Eocene

Palaeocene

Ear

ly C

reta

ceou

sL

ate

Cre

tace

ous

GEOLOGICEPOCHSAND AGES

FOSSILS FROM SEDIMENT ABOVEBASALT IN DSDP DRILL HOLES (Rangeof each fossil shown by a vertical line)

160

150

140

130

120

110

100

90

80

70

60

50

40

30

20

10

0

Rad

iom

etri

c ti

me

scal

e (m

illi

ons

of y

ears

)

Brotzenia Saccocoma

Retalipora Hedbergella

25×

Globotruncana maya.

Lenticulina

25×

Globigerina

Uvigerina

32×Globorotalia

82×

Orbulina

36×

4×35×

Bairdia

25×

42×

42×

Globotruncana forn.

42×25×

DIAGRAM C

40

Marks

Brice, J, Levin, H & Smith, M, Laboratory Studies in Earth History, 6th ed 1997, Wm C Brown Publishers, Dubuque, Iowa, pp51-53.


Diagram D shows the location of four DSDP drill holes and the micro-fossilsrecognised in each hole.

KEY: • 105 — DSDP Hole 105

1 From the data given in Diagram C, name ONE micro-fossil thatcould be a good index fossil. What other characteristic must thefossil have to be a good index fossil?

2 What is the radiometric age range of the fossil assemblage inDSDP hole 11?

3 What is the minimum age of the basalt in DSDP hole 105?

4 Discuss how micro-fossils are used as stratigraphic tools in thepetroleum industry.

End of paper

DSDP hole 105Water depth 5231 mHole depth 633 m

Siltyclay

ClayDarkclayLime-stoneBasalt

DSDP hole 10Water depth 4712 mHole depth 459 mChalk

ooze

Basalt

Chalkooze

Basalt



Marlooze

Basalt

Clay

......................................................................................................................

.................

.

....................................................................................................

..............

....20

0 m

2000

m

AfricaNorth

Amer

ica

Atlantic Ocean

Bermuda

Cape Verde Is.

Canary Is.

75° 60° 45° 30° 15°

20°

20°

30°

40°

10510

11 137

DIAGRAM D

41

Marks

BLANK PAGE

42

BLANK PAGE

43


2000

GEOLOGY2 UNIT

PART B ANSWER BOOK


• Write your Student Number and Centre Number at thetop right-hand corner of this page.

• You should receive this Answer Book with a Part AAnswer Sheet, a Part C Answer Book, and an ElectiveAnswer Book.

• Answer Questions 16 to 25 in this Answer Book.


342

STUDENT NUMBER

CENTRE NUMBER

MARKER’S USE ONLY

PART

B

Mark Marker Check

PART B

Each question is worth 3 marks.

Answer the questions in the spaces provided.

16 (a) ......................................................................................................................

......................................................................................................................

(b) ......................................................................................................................

......................................................................................................................

......................................................................................................................

(c) ......................................................................................................................

......................................................................................................................

17 (a) ......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

(b) ......................................................................................................................

2

MARKER’SUSE ONLY

18 (a) (i) ............................................................................................................

(ii) ............................................................................................................

............................................................................................................

(b) ......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

19 (a) ......................................................................................................................

(b) ......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

3

MARKER’SUSE ONLY

20 1st Evidence .........................................................................................................

...............................................................................................................................

...............................................................................................................................

2nd Evidence ........................................................................................................

...............................................................................................................................

...............................................................................................................................

3rd Evidence .........................................................................................................

...............................................................................................................................

...............................................................................................................................

21 (a) ......................................................................................................................

......................................................................................................................

(b) ......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

4

MARKER’SUSE ONLY

22 (a)

(b) (i) ..........................................................................................................

..............................................................................................................

..............................................................................................................

..............................................................................................................

..............................................................................................................

..............................................................................................................

(ii)

3·8–5·6 Ma

Sea level

2·3–3·3 Ma1·3–1·8 Ma

0–1·3 Ma0–0·7 Ma

5

MARKER’SUSE ONLY

23 Problem 1 .............................................................................................................

...............................................................................................................................

...............................................................................................................................

Problem 2 .............................................................................................................

...............................................................................................................................

...............................................................................................................................

Problem 3 .............................................................................................................

...............................................................................................................................

...............................................................................................................................

6

MARKER’SUSE ONLY

(b) Reason 1 ......................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

Reason 2 ......................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

Please turn over

W E

KEY

Conglomerate

Shale

Sandstone

Limestone

0 1 2 km

24 (a)

7

MARKER’SUSE ONLY

25 ...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

8

MARKER’SUSE ONLY



2000

GEOLOGYUNIT

PART C ANSWER BOOK


• Write your Student Number and Centre Number at thetop right-hand corner of this page.

• You should receive this Answer Book with a Part AAnswer Sheet, a Part B Answer Book, and an ElectiveAnswer Book.

• Answer Questions 26 to 31 in this Answer Book.


343

STUDENT NUMBER

CENTRE NUMBER

MARKER’S USE ONLY

PART

C

Mark Marker Check

PART C

Each question is worth 5 marks.

Answer the questions in the spaces provided.

26 (a) ......................................................................................................................

(c) ......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

(b)

2

MARKER’SUSE ONLY

27 (a) ......................................................................................................................

......................................................................................................................

(b) ......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

(c) Problem 1 ....................................................................................................

......................................................................................................................

Problem 2 ....................................................................................................

......................................................................................................................

(d) ......................................................................................................................

......................................................................................................................

......................................................................................................................

3

MARKER’SUSE ONLY

28 (a) ......................................................................................................................

(b) ......................................................................................................................

......................................................................................................................

......................................................................................................................

(c) ......................................................................................................................

......................................................................................................................

......................................................................................................................

(d) ......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

4

MARKER’SUSE ONLY

29 (a) ......................................................................................................................

(b) ......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

(c) Oldest ..........................................................................................................

......................................................................................................................

Youngest ......................................................................................................

(d) ......................................................................................................................

......................................................................................................................

......................................................................................................................

......................................................................................................................

5

MARKER’SUSE ONLY

30 ...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

6

MARKER’SUSE ONLY

31 (a) ........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

(b) ........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

(c) ........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

7

MARKER’SUSE ONLY

BLANK PAGE

8


geology - board of studies your answers in either blue or black pen ... new zealand journal of...

Documents